Electric burglar-alarm.



PATBNTED JAN, 3, 1905.

F. S. HOLMES.

ELECTRIC BURGLAR ALARM.

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APPLIOATION RILED MAY 17, 190 1.

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PATENTBD JAN. 3, 1905.

P. S. HOLMES.

ELECTRIC BURGLAR ALARM.

APPLICATION FILED MAY 17,1904.

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n W ATTOWfl v No. 778,971. PATENTED JAN. 3, 1905.

' P. S. HOLMES.

ELECTRIC BURGLAR ALARM.

7 APPLICATION FILED MAY 17, 1904.

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WITNESSES.

'ATTORNE ELECTRIC BURGLAR ALARM.

APPLICATION FILED MAY 17, 1904.

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Patented January 3, 1905.

PATENT OFFICE.

FRANKLIN S. HOLMES, OF NEW YORK, N. Y.

ELECTRIC BURGLAR-ALARIVI.

SPECIFICATION forming part of Letters Patent No. 778,971, dated January 3, 1905.

Application filed May 1'7, 1904. Serial No. 208,413.

To (LZZ whom it may concern:

Be it known that I, FRANKLIN S. HOLMES, a citizen of the United States of America, residing at New York city, in the county of Kings and State of New York, have invented certain new and useful Improvements in Electric Burglar-Alarms, of which the following is a specification.

My invention has reference to improvements in electric protective systems against burglary, and more particularly to that class of such systems utilizing a closed circuit eX- tending from the indicating apparatus at the protective office to the structure to be protected.

The device consists in so arranging at the protective office and at the protected structure distributed resistances which are variable at will in a single protective circuit actuated from a common source of electric potential that it becomes impossible to successfully meddle with the protective circuit, and thus substitute a different course having equal resistance for that portion of the electrical circuit affording the protection.

I am aware that it has been proposed, as in Patent No. 554,505, issued to O. Coleman, to operate by the use of three circuits between the central ofiice and the protected structure two resistance-changers having their variable resistances in series in the protective circuit, one changer being located at the central oflice and one at the protected structure, and both changers being so adjusted together that while the resistance placed in circuit at any time by each changer may vary, the resistance placed in circuit at any time by both changers would be fixed, and thus not disarrange the indicating apparatus. I am also aware that it has been proposed,as in Patent No. 598,049, issued to O. Coleman, by the use of one electric circuit between the central oflice and the protected structure to arrange two groups of battery-cells in every protective circuit, one group being located at the central oflice and one group at the protected structure, and to so manipulate them by simultaneous magnetic control that while each group may furnish a variety of potentials the two groups together shall furnish the protective circuit but one potential, thus not disarranging the indicating apparatus; but it is desirable in the business of electric protection to confine the service, if possible, to one circuit between the central oflice and the protected structure and to make the source of potential used for one protection-circuit common to all protective circuits and to locate it all at the central station.

The present invention requires electric potential from two sources of differing strength, but so located that they may be common sources to an indefinite number of protective circuits. It also requires but one electric circuit between the protective oflice and the protected structure.

In Patent N 0. 619,448, issued to James Tomney, there is disclosed a device for changing at will the resistance in the circuit of the protected structure, which change is indicated by the position of the galvanometer-needle at the central station. ratus is that for every such change in said resistance the galvanometer-needle takes up a new position, and so requires a readjustment of the local-circuit-closing mechanism actuated by the galvanometer-needle. As a result the mechanism under this patent has been operated simply to test the proper continuity of the circuit between the central ofiice and the protected structure, which, having been ascertained, the normal resistance is again inserted at the protected structure.

My present invention consists in placing two resistance-changers similar in design and mechanism to that of the Patent N 0. 619,448 in series in the protective circuit and so arranging the varying resistances which each of said resistance-changers individually controls that their sum shall be constant and alternately Zero. One of these resistance-changers is located at the central station and the other within the protected structure, and both are simultaneously actuated by a heavy batterycurrent controlled by the operator at the central station. It will therefore be readily understood that the galvanometer-needle takes but two positions at the central station even though the resistance of the circuit within the protected structure may vary within wide limits, these positions being determined by either One objection to this appathe constant or zero position of the changers. Tampering with the wiring at the protected structure or substituting other resistance therefor becomes unsuccessful because of the variable resistances in circuit at this point.

The nature of my invention will best be understood when described in connection with the accompanying drawings, in which Figure 1 represents a diagrammatic view illustrating my improved system. Fig. 2 is a plan or top view of the resistance-changer and accompanying parts. Fig. 3 is a side elevation of the same. Fig. 4 is a side view illustrating a mechanical instead of an electrical form for the resistance-changer. Fig. 5 is a rear view of Fig. 4. Fig. 6 represents a diagrammatic view illustrating my invention.

Similar letters and numerals of reference designate corresponding parts throughout the several views of the drawings.

Referring to Figs. 2 and 3 of the drawings, numeral 1 designates the base of the instrument, to which are secured the electromagnets M. 4 designates a frame, to which is pivoted the shaft 6, carrying the armature 5, the latter being provided with a tailpiece 7, which is connected by a spring 8 and adjustingscrew to a post 2 on the base 1 for adjusting the tensionof the armature. Also journaled to the frame 1 is an armature 10, provided with a counterbalance 11 and with a contactarm 12, which upon movement of the said armature toward the electromagnets comes into contact with a contact-post 13. On the commutator-shaft 18, which is made of nonconducting material, is mounted a ratchet-wheel 19, adapted to be engaged by a spring-pawl 22, pivoted to anarm 20, extending from the armature 5. On the shaft 18 are mounted the commutator D and the circuit changer J, which may be of any usual construction. R

' R R are the resistances adapted to be switched in successively by the turning of the commutator.

Referring now to Fig. 1, the apparatus and connections at the protected structure are indicated at the right of the line L L and those at the central station are indicated at the left of the same line. Gr designates the galvanometer, disturbances of the needle of which are indicated by the alarm devices shown. B is a source of electricity of low potential which is normally included in the protective circuit, as follows: One pole of said battery is connected with one of the binding-posts of the galvanometer G through wire 30, while the other pole is grounded, as at g, and also placed in connection with the high-potential battery B. From another post of the galvanometer this battery-circuit passes over wire 31 to one contact of battery-key K, thence through wire 32 to electromagnets M of the resistance -changer D, through wire 33 to commutator-brush C of resistance-changer, wire 34 to line-wire Z, thence through wire 34. to electromagnet M of the resistancechanger D at the protected structure, Wire 35 to a section of the protective wiring F of the premises, wire 36 to commutator of resistance-changer D fromthence through wire 37 to remaining section of protective wiring F of premises, over wire 38 to circuitchanger W of resistance O, wire 39, switch 0, signal-bell E wire 40 to ground at g, and back to battery B through 9.

When the battery-key K is pressed, contact is broken at wire 31 and made at wire 42, leading from the high-potential battery B, and battery B and galvanometer G are accordingly cut out. The circuit from battery B is then as follows: wire 42, key K, wire 32 the same as before, except that the strong current sent out through magnet M actuates the armature 10 to close a short circuit by wire 43 from wire 33 to wire 34 around the resistances of the resistance-changer D. This strong current also causes M at the protected structure to similarly actuate its armature 10 and close a short circuit by wire 39 around the protective resistance and the resistancecoils of the resistance-changer from wire 35 to the circuit-breaker VV The protective circuit now has all its important resistances short-circuited and the magnets M and M become strong enough to actuate their heavy armatures 5, respectively. These armatures being attracted rotate the commutator-shafts of the two resistance-changers, thereby changing the resistance coils in circuit in each changer.

If the shunt-circuit 11 around the bell E is open at switch attachment A, the bell will strike each time the key K is depressed. The operator at the central station can therefore actuate both resistance-changers D and D and bell E each time he depresses key K, and thus introduce successive resistances at the changers and give signals. When the operator removes pressure from key K, it again closes contact to wire 31, and so through the galvanometer and low-potential battery B, at which time all four' armatures are released by their magnets M and M and the protective circuit is reestablished through the coils of the galvanometer, the two resistance-changers D and D and the protective wiring at F.

The commutator-segments on the two resistance-changers marked with even numbers are connected together without appreciable resistance. At D they are connected to wire 33 and at D to wire 36. It will be noted that the odd segments of the commutators are connected together through the resistance-coils R R B In case of D the segment 1 is connected to wire 33 and in case of D segment 8 is connected to wire 36. It follows,therefore, that when brush C rests upon segment 2 and brush O upon segment 2 the resistances of both changers are cut out of circuit. When again O rests upon segment 1 and C upon segment 1, resistance of changer D is cut out, but resistance of three coils at D is in circuit. Consequently if the six coils of D and D have the same resistance, three of them always being in circuit when the brushes of the two changers respectively rest upon the segments of the commutators bearing the same odd number, the total resistance through the two changers will be constant, or, in other words, the resistances will be complemental.

At S is a switch normally open, which when 'closed cuts out the magnets M and the resistance-changer D. This switch is used to advance one resistance changer without the other, so as to bring their commutators either into or out of complemental balanced relations.

At A is indicated the usual short-circuiting attachment-spring placed upon doors or windows of the protected structu re. It is normally open and closes to cut out resistance when openings are made, thereby affecting the indicating-needle of the galvanometer Gr.

At A is a short-circuiting spring-shunting signal-bell E This spring closes the circuit when a door in the protected structure, as that of a safe, is closed, so cutting out the bell E automatically.

The local circuit at the central station controlled by galvanometer-needle comprises a local battery B switches S and S and a relaycircuit containing battery Bibell E, annunciator T, and contacts of relay M as usual.

It will be observed that the resistancechanger at the central station may be operated mechanically instead of electrically. This is accomplished, as shown in Figs. 4, 5, and 6, When the key K is made to rotate a brush f traversing the segments of the commutator D.

This commutator is connected up precisely as the commutators in the magnetic changers previously described, even segments being connected without resistance and odd ones with resistances in series and of equivalent amount and arrangement to that provided for magnetic changer M. In this mechanical form the function of the armatures to cut out the coils of the changer, as in the magnetic changers, is accomplished by the contact-arm g and springs it and 71, which make contact when key K is depressed, thereby directly connecting wires 42 and 1.

In the mechanical arrangement it is also necessary to furnish means for actuating one of the resistance-changers without the other, as was accomplished by closing switch S to shunt out changer M when it is desired to change the complemental relations of the resistancechangers. This is done in the case of the mechanical changer by inserting the switch t,

Fig. 6, normally closed in wire 42; When this switch is opened, key K can be manipulated without sending heavy battery-current through the circuit. The resistance-changer D therefore remains inoperative.

What I claim as new is 1. The combination with a central station, a guarded structure and a single electric protective circuit connecting them, and two sources of electric potential common to the central station for energizing the circuit at will by either of them, of a variable resistance, located in the circuit at the central oflice, in series with a variable resistance located in the circuit at the guarded structure, and means at the central station for simultaneously changing both resistances.

2. The combination with a central station, a guarded structure and a single electric protective circuit connecting them, and two sources of electric potential common to the central station for energizing the circuit at will by either of them, of a variable resistance located in the circuit at the central station, a variable resistance located in the circuit at the guarded structure, and means at the central station for changing at will either one of said resistances.

3. The combination with a central station, a guarded structure, and a single electric protective circuit connecting them, and two sources of electric potential common to the central station for energizing the circuit at will by either of them, of. a variable complemental resistance, located in the circuit at the central otlice, in series with a variable complemental resistance located in the circuit at the guarded structure, both resistances being controlled magnetically and simultaneously by the action of the stronger source of potential.

4. The combination with a central station, a guarded structure and a single electric protective circuit connecting them, and two sources of electric potential common to the central station for energizing the circuit at will by either of them, of a variable complemental resistance located in the circuit at the central office, and a variable complemental resistance located in the circuit at the guarded structure, and a switch shunting the resistance at the central office to cause the stronger battery, when brought into circuit, to actuate only the resistance at the guarded structure.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

FRANKLIN S. HOLMES. l/Vitnesses:

A. FABER DU FAUR, Jr., RAENA H. YUDIZKY. 

